1. Field of the Invention
The present invention relates to a subcool and/or precool system for the liquid refrigerant and/or hot gas discharge refrigerant of an ice machine that utilizes the harvest water and/or melt water from said ice machine for purposes of increasing the capacity and efficiency of said ice machine.
The present invention further relates to a system for capturing the harvest and/or melt water for utilization in the subcool/precool system.
The present invention also relates to a system for controlling the flow of said harvest and/or melt water through heat exchangers for purposes of subcooling and/or precooling the refrigerant.
The present invention additionally relates to a system for utilizing the harvest and/or melt water as a heat sink (no active pumping) for said subcooling and/or precooling of the refrigerant.
The present invention also further relates to a system for using excess refrigeration capability due to subcooling for purposes of precooling the incoming water supply.
Still further, the present invention relates to a system for using excess refrigeration capability due to subcooling for purposes of chilling the ice holding compartment to prevent excessive melt or degradation of ice that has already been produced.
Finally, the present invention relates to a method for downsizing the compressor of an ice machine to more closely match the refrigeration capability of the ice making plate with the additional capability due to the subcooling taken into account.
This invention more particularly pertains to an apparatus and method comprising a harvest and/or melt water-cooled subcooler positioned between a conventional air source or water source ice machine condenser and the evaporator. This invention also more particularly pertains to an apparatus and method comprising a harvest and/or melt water cooled precooler positioned between the compressor discharge of a conventional air source or water source ice machine and the condenser for said ice machine.
Next, this invention more particularly pertains to an apparatus and method whereby said harvest and/or melt water may be used first in said subcooler and then subsequently used in said precooler.
Additionally, this invention more particularly pertains to an apparatus and method comprising a reservoir for capturing and storing said harvest and/or melt water.
This invention also more particularly pertains to an apparatus and method comprising a pump and controls for purposes of directing and controlling the flow of said harvest and/or melt water through said subcooler and/or precooler heat exchangers.
This invention alternately more particularly pertains to an apparatus and method to direct said harvest and/or melt water into heat sink reservoirs for purposes of subcooling and/or precooling the refrigerant of an ice machine, without the use of directed flow heat exchangers.
This invention additionally more particularly pertains to an apparatus and method comprising an incoming water precooler positioned between the incoming water supply and the water control valve or after the water control valve but before the ice machine water reservoir and that is further positioned in the refrigerant circuit between the outlet of the ice making evaporator and the inlet to the compressor, whereby excess refrigeration effect due to subcooling may be used to precool the incoming water supply to said ice machine.
Also, this invention more particularly pertains to an apparatus and method comprising a secondary evaporator positioned between the outlet of the ice making evaporator and the inlet to the compressor, whereby excess refrigeration effect due to subcooling may be used to cool the ice holding compartment of the ice machine system.
Finally, this invention also more particularly pertains to an apparatus and method comprising the downsizing of the compressor of an ice machine to more closely match the ice production capability of the ice making evaporator to a compressor sized for the refrigeration capacity capability due to the subcooling accomplished by the harvest and/or melt water.
2. Description of the Background Art
Presently there exist many types of devices designed to operate in the thermal transfer cycle. The vapor-compression refrigeration cycle is the pattern cycle for the great majority of commercially available ice machine systems. This thermal transfer cycle is customarily accomplished by a compressor, condenser, throttling device and evaporator connected in serial fluid communication with one another. The system is charged with refrigerant, which circulates through each of the components. More particularly, the refrigerant of the system circulates through each of the components to remove heat from the evaporator and transfer heat to the condenser. The compressor compresses the refrigerant from a low-pressure superheated vapor state to a high-pressure superheated vapor state thereby increasing the temperature, enthalpy and pressure of the refrigerant. A superheated vapor is a vapor that has been heated above its boiling point temperature. It leaves the compressor and enters the condenser as a vapor at some elevated pressure where the refrigerant is condensed as a result of the heat transfer to cooling water and/or to ambient air. The refrigerant then flows through the condenser condensing the refrigerant at a substantially constant pressure to a saturated-liquid state. The refrigerant then leaves the condenser as a high pressure liquid. The pressure of the liquid is decreased as it flows through the expansion valve causing the refrigerant to change to a mixed liquid-vapor state. The remaining liquid, now at low pressure, is vaporized in the evaporator as a result of heat transfer from the refrigerated space. This vapor then enters the compressor to complete the cycle. The ideal cycle and hardware schematic for vapor compression refrigeration is shown in FIG. 1 as cycle 1-2-3-4-1. More particularly, the process representation in FIG. 1 is represented by a pressure-enthalpy diagram, which illustrates the particular thermodynamic characteristics of a typical refrigerant. The P-h plane is particularly useful in showing the amounts of energy transfer as heat. Referring to FIG. 1, saturated vapor at low pressure enters the compressor and undergoes a reversible adiabatic compression, 1-2. Adiabatic refers to any change in which there is no gain or loss of heat. Heat is then rejected at constant pressure in process 2-3. An adiabatic pressure change occurs through the expansion device in process 3-4, and the working fluid is then evaporated at constant pressure, process 4-1, to complete the cycle. However, the actual refrigeration cycle may deviate from the ideal cycle primarily because of pressure drops associated with fluid flow and heat transfer to or from the surroundings. It is readily apparent that the temperature of the liquid refrigerant plays an important role in the potential for removing heat in the evaporator phase of the thermal cycle. The colder the liquid refrigerant entering the evaporator, the greater the possible change in enthalpy or heat energy absorbed per unit mass of liquid available for vaporization and the colder the liquid refrigerant entering the expansion device leading to the evaporator, the lower the flash gas loss, which means a higher portion or percentage of mass is available for vaporization through the evaporator. Finally, it is readily apparent that rapid precooling of the hot gas discharge from a compressor lowers power consumption, reduces heat discharge by an air cooled condenser, improves compressor efficiency and improves the primary condenser's performance. Many such devices and methods currently exist that are designed to accomplish this subcooling and precooling.
However, these known methods and devices have drawbacks. The drawbacks include high cost of accomplishing the subcooling and/or precooling, and/or the ineffectiveness or degrading effectiveness of the subcooling and/or precooling, method and/or device.
In response to the realized inadequacies of earlier methods and devices, it became clear that there is a need for a liquid refrigerant subcooler for an ice machine that has a low initial cost as well as having a method for utilizing the previously unused, very cold heat sink available in the form of the harvest and/or melt water being discharged and subsequently thrown away from an ice machine.
It is also readily apparent that rapid precooling of the hot gas discharge from a compressor reduces head pressure, decreases power consumption, reduces heat being discharged into the ambient air surrounding an ice machine and improves the efficiency of the primary condenser of an ice machine system.
The use of the harvest and/or melt water coming off of the ice machine or even after use in the subcooler will provide this precooling in a very cost effective manner.
Therefore the principal objective of this invention is to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the subcooler and precooler art for ice machines.
Another objective of the present invention is to provide a more constant and colder subcooling over a wide range of air source conditions.
Still another objective of the present invention is to provide harvest and/or melt water cooling to the liquid refrigerant of an ice machine system.
Yet another objective of the present invention is to provide increased refrigeration capacity and ice making capacity by means of the subcooling of the liquid refrigerant.
An additional objective of the present invention is to provide a means of utilizing excess refrigeration capacity due to subcooling by adding an evaporator surface that will precool the incoming water supply.
Still a further objective of the present invention is to provide a means of utilizing excess refrigeration capacity due to subcooling by adding an evaporator surface that will cool the ice storage chamber/compartment.
Yet a further objective of the present invention is to provide a means of downsizing the ice machine compressor to compensate for excess refrigeration capacity due to subcooling of the liquid refrigerant.
Still yet another objective of the present invention is to provide rapid precooling of the hot gas discharge from a compressor utilizing the harvest and/or melt water from and ice machine system, or after first using said harvest and/or melt water to subcool the liquid refrigerant.
And yet another objective of the present invention is to provide lower power consumption, increased pumping efficiency of the compressor, decreased heat rejection to the ambient air surrounding an ice machine, as well as to improve the primary condenser's performance.
Even yet another objective of the present invention is to provide a means for capturing, storing and preventing heat gains to the harvest and/or melt water discharge from an ice machine system.
And yet another objective of the present invention is to provide a means for pumping and controlling the flow of the stored harvest and/or melt water through the subcooler and/or precooler heat exchangers.
And yet another objective of the present invention is to provide an alternative means of utilizing the harvest and/or melt water to subcool and/or precool the refrigerant of an ice machine, by providing thermal heat sink storage tanks where subcooling and/or precooling with the total harvest and/or melt water available from each cycle may be accomplished in lieu of pumping said harvest and/or melt water through subcooler and/or precooler heat exchangers.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrations of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure.
Accordingly, other objects and a more comprehensive understanding of the invention may be obtained by referring to the summary of the invention, and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.